In recent years, a steering switch as a steering wheel input device is widely used to perform operations of a car navigation system, an audio system, an air conditioning system, and the like in a vehicle. The steering wheel input device is connected to a control device which controls the car navigation system, the audio system, and the air conditioning system in the vehicle. The steering wheel input device is disposed on a front face of a steering wheel.
Such a steering wheel input device will be described with reference to FIGS. 8 and 9.
FIG. 8 is a cross-sectional view of steering wheel input device 15. FIG. 9 is an exploded perspective view of conventional steering wheel input device 15.
Steering wheel input device 15 includes circuit board 1, supporting plate 5, movable plate 6, touch sensor 9, display plate 10, lower cover 7, and upper cover 11.
On an upper surface of circuit board 1, control circuit 2 such as a microcomputer, a plurality of light emitting elements 3 such as LEDs (Light Emitting Diodes), and push switch 4 are mounted. Patterns are formed on both the upper surface and a lower surface of circuit board 1. Light emitting elements 3 and push switch 4 are connected to control circuit 2 through the patterns.
Moreover, supporting plate 5 made of a resin is disposed above circuit board 1. A plurality of through-holes 5A are disposed in supporting plate 5. Each of the plurality of through-holes 5A is provided corresponding to each of the plurality of light emitting elements 3. Through-holes 5A penetrate supporting plate 5 in a vertical direction.
Movable plate 6 made of a resin is disposed above supporting plate 5. A plurality of transparent windows 6A are provided in movable plate 6. Transparent windows 6A transmit light in a vertical direction of movable plate 6. Each of the plurality of transparent windows 6A is provided corresponding to each of the plurality of light emitting elements 3. Light emitted from light emitting elements 3 passes upward from circuit board 1 through through-holes 5A and transparent windows 6A. Rod-shaped shaft 8 is inserted at one end of movable plate 6.
Circuit board 1, supporting plate 5, and movable plate 6 are disposed on lower cover 7. Bearing 7A is disposed on lower cover 7. Bearing 7A retains shaft 8 of movable plate 6. With this configuration, movable plate 6 can tilt with shaft 8 as a supporting point. Push switch 4 is pressed by the tilt of movable plate 6 and thus is switched between on and off.
Moreover, touch sensor 9 is disposed above transparent windows 6A provided in movable plate 6. Touch sensor 9 includes wiring cable 9A, and wiring cable 9A extends from touch sensor 9. Wiring cable 9A is connected to control circuit 2 in circuit board 1. When an operator touches touch sensor 9, control circuit 2 detects that touch sensor 9 is operated.
Display plate 10 is disposed above touch sensor 9. A plurality of operation parts 10A and a plurality of translucent parts 10B are disposed in display plate 10. Each of the plurality of operation parts 10A is provided corresponding to each of the plurality of light emitting elements 3. Translucent parts 10B respectively corresponding to operation parts 10A are disposed near operation parts 10A.
Upper cover 11 has hole part 11A. Upper cover 11 covers display plate 10 such that display plate 10 is exposed through hole part 11A. As described above, steering wheel input device 15 is configured.
Steering wheel input device 15 configured in this manner is disposed on a front face of a steering wheel of a vehicle such that display plate 10 is exposed.
When the operator touches one of the plurality of operation parts 10A, control circuit 2 detects a position where the touching operation is performed on touch sensor 9. Control circuit 2 controls such that light emitting element 3 corresponding to the operated operation parts 10A emits light, to allow translucent part 10B near the operated operation parts 10A to emit light. Further, when the operator pushes display plate 10, movable plate 6 is tilted and push switch 4 is turned on. Then, control circuit 2 outputs a signal corresponding to the operated operation part 9A to the control device connected to steering wheel input device 15.
Note that, for example, PTL 1 is known as information on prior art documents similar to the invention of this application.